Multistage refrigerating apparatus



April 12, 1949. w. L. MORRISON MULTISTAGE REFRIGERATING APPARATUS 8Sheets-Sheet 1 Filed Dec. 21, 1942 n A. L

April 12, 1949. 'w. L. MORRISON MULTISTAGE REFRIGERATING APPARATUS FiledDec. 21, 1942 Irzve nto 7- ilzZ'ZardL Jforrzjiorz/ dmmim Jlttorr ze yp'April 1949- w.- L. MORRISON 7,

MULTISTAGE REFRIGERATING APPARATUS Filed Dec. 21, 1942 a Sfieets-Sheet sIn verzzfo r I hzZZardZJforrg-iwz QMaLrwQ-J April 1949- w. MORRISON2,467,219

MULT I STAGE REFRIGERAT ING APPARATUS Filed Dec. 21, 1942 8 Sheets-Sheet4 V [rave/721507" 43 Mi'ZZardLJfarfzjsora @G MJZZwD April 12, 1949. w.MORRISON 2,467,219

MULTISTAGE REFRIGERATING APPARATUS Filed Dec. 21, 190. a She ets-Sheet 5@UMhvdnsw April 12, 1949.

W. L. MORRISON MULTISTAGE REFRIGERATING APPARATUS Filed Dec. 21, 1942 lV l i I 53 8 Sheets-Sheet 6 April 12, 1949.

w. L. MORRISON IUL'I'ISTAGE REFRIGERATING APPARATUS 8 Sheets-Sheet '7Filed Dec. 21, 1942 all/drill! Elmwmmw I/ll/ lllI/l I vz'uen-orWiZZaraZZ .Morrzjson April l2,' 1949. w. L. MORRISON MULTISTAGEREFRIGERATING APPARATUS 8 Sheets-Sheet 8 Filed D60. 21, 1942 In-ueni'orWE'ZZaraZ .LJfirrzl sorz w M TN gut) Patented Apr. 12, 1949 UNITEDSTATES PATENT OFFICE MULTISTAGE REFRIGERATING APPARATUS Willard L.Morrison, Lake Forest, Ill.

Application December 21, 1942, Serial No. 469,672

6 Claims.

This invention relates to a refrigerating apparatus and has for itsobject to provide a new and improved apparatus of this description.

The invention has as a further object to provide a refrigeratingapparatus whereby a very low temperature, below 120 degrees Fahrenheit,is produced by means of a multistage method.

The invention has as a further object to provide a refrigeratingapparatus wherein the heat from the evaporator or cold chamber, in whichthe low temperature is produced, is first reduced by an intermediateheat exchanger with one refrigerating apparatus, and is then furtherreduced by another heat exchanger in connection with anotherrefrigerating apparatus.

The invention has as a further object to provide a multistage means forcontinuously producing a very low temperature, such as 120 degreesFahrenheit,

In addition to freezing foods, this invention has numerous other usessuch as in preserving blood plasma, shrinking one metal part that is tofit into another part so that the parts can be connected by hand withoutinjuring either part, dessicating food products, hardening cutting toolsfor working on metals, and to emulate the conditions found at thehighest altitudes reached the proper working of the instruments underthese high altitudes. In order that the devices in the evaporator may bekept under observation, the evaporator may be provided with atransparent top, or the top may be left off.

The invention has as a further object to provide a refrigeratingapparatus for separating the oil from the refrigerant and controllingthe oil level.

The invention has as a further object to provide a refrigeratingapparatus wherein there is utilized means for spraying liquidrefrigerant into the hot gases from the compressor during the process ofcooling these hot gases.

The invention has as a further object to provide a refrigeratingapparatus wherein there is utilized a float chamber with an open typefloat and a mercury switch controlled thereby.

The invention has as a further object to provide a refrigeratingapparatus wherein the heat is removed from the gas leaving theevaporator in two stages, In the first stage, the heat is extracted bythe evaporation of an extremely vola-- tile refrigerant such as ethane,and the second stage is extracted by the use of a different gas such aspropane.

,tor shown in'Fig. 3;

Fi 5 is a sectional view taken on line 55 of Fig. 3;

Fig. 6 is a plan view of the float switch;

Fig. 7 is a sectional view taken on line l-| of Fig. 6;

Fig. 8 is a sectional view taken on line 88 of Fig. 7;

Fig. 9 is a sectional view of the electro-magnetic valve taken on line99 of Fig. 10;

Fig. 10 is a sectional view taken on line Ill-l0 of Fig. 9;

Fig. 11 is a sectional view taken on line lI-|l of Fi 10;

I Fig. 12 is a sectional view taken on line l2l2 of Fig. 9;

Fig. 13 is a sectional view taken on line Iii-l3 of Fig. 9;

Fig. 14 is a view or the under side of the valve plate shown in Figs. 9and 12;

Fig. 15 is a view in part section showing the venturi, taken on linel5l5 of Fig. 1;

Fig. 16 is a longitudinal sectional view through the oil separator;

Fig. 17 is a sectional view taken on line l'l-ll of Fig. 16;

Fig. 18 is a plan view of the top of the 'conone refrigerating apparatusand from the intermediate heat interchanger to the atmosphere by meansof another refrigerating apparatus.

In the device as shown there are three principal elements which aredesignated A. B and C. Element A is the evaporator or cold chamber whichmay be of any suitable construction but which is preferably of the typeshown in Patent No. 2,356,779 issued August 29, 1944. This evaporator,designated generally by the numeral 6, comprises two cylinders Ia, lb ofheat conducting material with a space between them in which is located aseries of passageway forming elements Ic. These passageway formingelements are shorter than the cylinders and every alternate elementextends from the top of the cylinders to a point near the bottom of thecylinders and every other of the passageway forming elements extendsfrom the bottom of the cylinders to a point near the top of thecylinders, so that there are a plurality of passages extending parallelto the cylinders and connected together at the top and bottom so as toform a continuous back and forth passageway in the space between thecylinders. The space between the edges of the cylinders at the top andbottom are closed and sealed.

The passageway forming elements Ic are rods preferably cylindrical inshape. These rods are loosely held in between the .cylinders Ia and I?)that. a portion of the refrigerant, which is passing along thesepassages when the device is in operation, will leak past them so as tocontact the entire surface of the cylinders and make the cylinderscontinuous primary cooling surfaces. The cylinders Ia and lb aresurrounded by heat insulating material Id.

The element B comprises a refrigerating apparatus consisting of theusual compressor and a motor for operating it, which compressor receivesthe vaporized refrigerant from the evaporator of element A andcompresses it and delivers it to the condenser-receiver I intermediatethe elementsB and C. This refrigerant is an extremely volatilerefrigerant, such as ethane, and it is condensed from a vapor to aliquid and delivered to the expansion valve 5 and then to the evaporatorof element A.

Element C comprises a second refrigerating apparatus having the usualcompressor and motor for operating it. This element C uses a differentrefrigerant, less volatile than ethane, such as propane. Therefrigerating apparatus C has air cooled condensers and the condensedrefrigerant is passed through an expansion valve to the coil in thecondenser-receiver I and acts to cool the ethane refrigerant from therefrigerating apparatus B. The refrigerant ethane in thecondenser-receiver I collects as a liquid in the bottom thereof.

Referring now to Figs. 1 and 2, this liquid ethane refrigerant, while ata relatively high pressure is at a sub-zero temperature and passes fromthe bottom of the condenser-receiver I through central liquid tube 2(Figs. 18 and 19) and through an ethane liquid line 3, through a dryer 4to an electro-magnetic expansion valve 5 which is mounted in proximityto the annular cold chamber 6 or other evaporator in which it is desiredto produce the extremely low temperature.

The electro-magnetic expansion valve 5 is normally closed so that theethane is prevented thereby from entering the'evaporator 6.

The evaporator 6 is connected by a suction line I through a strainer 8by bulb 9 of a thermostatic switch 25 and a low pressure safety valveI0, into the inlet la of a throttling contactor 21,

separately shown in Figs. 3, 4 and 5. This throttling contactor has twofunctions, namely. to limit the maximum amount of pressure that can betransferred from the inlet through the outlet to the suction side of thecompressor, and by means of a mercury switch, to be hereafter described,to control the amount of pressure to which the suction side of thecompressor is subjected. From the outlet I I of the throttlingcontactor, a suction line IIa connects to the inlet I2b of an oilventuri I2 to the intake side of the compressor I3 which is driven by anelectric motor I3b.

Assuming that the compressor is running, the pressure will be reduced onthe outlet side I4 of the throttling contactor 21 which is connectedthrough multiple openings I5 to the outside of the metallic bellows I6.This reduction in pressure, when it reaches, a predetermined value, willcause the combined effect of spring I1 and the atmospheric pressure onthe inside ofbellows I6 to move the bottom end downwardly, as. shown inFig. 3, thereby moving the balanced valves I8 and I9 away from therespective seats and permitting gaseous refrigerant to flow through thevalves from the evaporator to the compressor. As the gaseous refrigerantin the evaporator is progressively removed, the resulting reduction inpressure causes the bottom end of the bellows I6 to move farther down sothat the attached rod 2|] operating through a stirrup 2I and a pivot 22will cause sufficient inclination of the mercury switch 23 so that themercury will move longitudinally within the switch and close contactbetween the points 24.

Because of the relative stiffness of bellows I6, there is a tendency todeflect the rod 20 from a truly central position so that if the valvesI8 and I9 were rigidly connected thereto there would be difficultyexperienced in having both of the valves I8 and I9seat centrally andaccurately into their respective seats. In order to eliminate thisdifficulty, the rod 20 has been separated from its corresponding rod 20aand interposed between them is a joint which maintains theirlongitudinal relation approximately intact, but permits lateral andangular freedom between them. To this end, a valve rod 20a is providedwhich terminates in a spherical end and which is held freely by the tworings 20!) and 200. These rings are free to move laterally within achamber formed by a ball housing 20d and abutment plug 20c. The axialrelation of the abutment plug 20c, which screws into a threaded openingin the housing 20f, and the dimensional relation between the facing ofthe housin thus formed being determinedby a spacer sleeve. The wholewith the ball forming a connection flexible angularly and laterally, andrelatively rigid longitudinally.

The points 24, (Figs. 2'and 21) are included in a 110 volt circuit inseries with a thermostatic control switch 25, (Figs. 2 and 21) aresistance lamp 26 (Figs. 2 and 21) and the electro-magnetic valve5(Figs. 2 and 21) so that when the circuit is closed through the mercurycontacting the switch points, current will fiow through the circult andoperate the electro-magnetic value 5, causing it to open and permittingliquid refrigerant to pass through pipe 5c and enter the evaporator Ii.This causes the rapid evaporation of the liquid refrigerant, causing animmediate increase of pressure in the evaporator and its associatedparts, which includes the bellows I of the throttling contactor 21(Figs. 2, 3 and 21),

and causes the bottom end of the bellows It to rise, causing an angularmovement of the mercury switch 23 which breaks the contact at the switchpoints 24, thereby permitting the electro-magnetic valve to close andstop the flow of refrigerant into the evaporator 6. This entireoperation ordinarily takes place in a short space of time so that theadmission of refrigerant into the evaporator takes place by very shortspurts. The evaporated refrigerant now passes from the evaporatorthrough suction line I, strainer 8 into the inlet In of suctionthrottling contactor valve 21 and through the valves I8 and I9 and outexit H and conductor Ila and through venturi I! into the low side ofcompressor l3 where it is compressed.

The compressed gas, now containing a small amount of oil which has beenintroduced from the crankcase of-the compressor I3, is now conductedthrough the pressure line 28 to a top central inlet '29 of an oilseparator 30 (Figs. 1,

2 and 16). The gas containing this small portion of oil goes down fromthe inlet 29 to a small aperture 3! on the side of an extension 29a ofthe inlet 29, which is of such size that the oily gas issues from it athigh velocity and impinges against the inside of a cylindrical tube 32.The diameter of this tube is relatively large with respect to theaperture. 3| so that the compressed orifices 34a, 35a and 36arespectively. The com pressed gas, now' completely freed of oil, issuesfrom an outlet 3'! and passes through a high side conductor tube 38 to asuperheat suppressing venturi 39, and from there into the top of thecondenser-receiver I. Interposed in the tube 38 between the oilseparator 38 and the condenserreceiver l are the check valve 38a and thehigh pressure safety valve 38b.

The superheat suppressing venturi 39, shown in detail in Fig. 20, causesthe hot gas to accelerate, by constant acceleration with respect totime, so that in the throat 40 the pressure of the gas has been reducedby the velocity to an amount lower than the pressure at either end ofthe venturi by several pounds per square inch.

6 the bottom as a liquid. The absorption of the super-heat by theatomized mist of refrigerant reduces very materially the amount ofsurface necessary in coil 42 to remove this latent heat forcondensation.

The oil, which has been separated from the compressed gases, flows downalong the sides of,

various cylindrical baflies and, since they are open at the bottom, theoil accumulates in the lower half of the oil separator and forms variouslevels in the various bailles due to the difference in pressure betweenthem, which differences produce the acceleration in the variousapertures. This oil has been removed from the compressor crankcase andit is necessary that it be returned when needed. To this end, we haveprovided a float chamber 43, shown separately in Figs. 6 and 7. Thisfloat chamber 43 is connected at the top by the tube 43d and at thebottom by tube 43c to the crankcase of the compressor 13, which assuresthat the level of the oil in the float chamber 43 is identical to thatof the crankcase of compressor l3. Within the float chamber 43 there isa hollow float 44, shown separately in Figs. 6 and 7, which is securedby a hinge member 44a so that as the level of the oil in the chamberchanges, theangular relation of float to the chamber varies.

Within the float chamber 43 is mounted a mercury switch 45, so placedthat the effect of the sudden changes in pressure in the inside of thefloat chamber which is likely to produce foaming of the oil, and as aconsequence, oil may become lodged within the float 44 through theopening 46, thereby altering its buoyancy. To elimi- The throat ofventuri 40 is connected by means of a tube 4! to the liquid tube 2 and,because of the low pressure at throat 40, liquid refrigerant mixes witha stream of hot compressed gas and higher than that of the liquid at thebottom thereof.

Within the condenser-receiver l, and placed as far as possible towardsthe upper end, is a cooling coil 42 which serves as an evaporator for aseparate refrigerating system C to be described later and which extractsthe latent heat from the compressed gas causing'it to condense and dropto nate this tendency, there is provided a tube 41 which passes throughthe opening 46 without making contact therewith and which tube isrigidly fastened to the top of the float chamber.

Mounted on the cover plate 43a is the bracket 43b having a pin 43cpivotally supporting the switch clip at its center. Near one end ofswitch clip 45a are pivoted the links 45b. The lower ends of links 45bare pivoted at 450 to the top of float 44. vIt will be noted that theprojected distance from the pin part 44a forming the hinge of the floatand the pivot 450 is many times greater than the distance between thepivots 43c and 45b, thus providing a multiplication of angular relationwhich causes operation of the mercury switch with a relatively smallchange in the level of the oil in the float chamber 43.

The lower end of the tube 41 is close to, but not in contact with, thebottom of float 44, and the tube 41 is connected by means of a tube 48to the throat of the oil venturi l2, shown in detail in Fig. 15. Thisthroat is at a considerably lower pressure than the inside of the float44 and any oil which may accumulate therein is thereby forced throughthe tubes 41 and 48 into the throat of the venturi l2, and the float 44is thereby kept relatively free from oil.

The bottom of the oil separator 30 is connected by a tube 49 through astrainer and dryer 5D and the electro-magnetic valve 5a to the bottom ofthe crankcase of the compressor l3. This electro-magnetic valve 50. iscontained in an electrical circuit including the float switch 45 and aresistance lamp 45a. This lamp also acts as a visible signal.

When, during the operation of the compressor, sufiicient oil has escapedfrom the crankcase of the compressor I3, thereby lowering the level inthe crankcase and at the same time in the float chamber of the fioat 44,so that the mercury switch 45 establishes contact in the circuit, theelectro-magnetic valve a, identical in construction with theelectro-magnetic valve 5, is thereby energized and opened, and oil fromthe separator 30 is returned to the crankcase of the compressor I3,until the level is sufliciently restored to again break the contact inthe switch 45.

In order to remove the latent heat from the oil free gas which has beenintroduced into the top of the condenser-receiver I, thereby causing itto condense into a liquid, we provide an additional refrigerating systemC quite similar in its construction to the one just described,illustrated at B. In this system liquid refrigerant, such as propane, isconducted from a receiver 5|, through a strainer 5Ia in the line BIb toa vapor filled thermostatic expansion valve 52, through a tube 52b tothe inlet 53 of the cooling coil 42, through a coil 42 by the outlet 54and tube 54b past the thermostatic bulb 52a, of expansion valve 52,through a strainer 54c, hand throttle 54d to the inlet Me to the venturiIL; and into the compressor l3a where it becomes compressed by thiscompressor which is driven by an electric motor I3c.

The compressed gas, now containing a small quantity of oil from thecompressor crankcase, is conducted through a pressure line 28a into theoil separator 30a and, after having had the oil removed in a mannerexactly analogous to that described'for the ethane compressor, the hotgas is conducted through a tube 55b to an adjacent air condenser 55,where a large proportion of the superheat is removed from the gas, andthen through tube 550 to the air condenser 55a of the other unit B,where the remainder of the superheat and all of the latent heat istransferred to the atmosphere and the condensed liquid is returned tothe receiver 5| by means of a tube 56.

Due to the interposition of the expansion valve 8 this bulb has beenchilled to a predetermined temperature, it causes the switch 25 to open,thereby preventing the further opening of the electro-magnetic valve 5and the further admission of liquid ethane into the annulus of the coldAs a consequence, the pressure of the chamber. refrigerant in thearinulusis progressively decreased until it reaches a value previouslydetermined as a minimum, The low side of a dual pressure control 51,which is connected by means of atube 58 to the crankcase of thecompressor I3, has been adjusted so that when this predetermined lowpressure has been reached, this dual pressure control break the circuitof the motor driving the compressor I3 and it ceases operating.

Under these conditions, heat is no longer being supplied to thecondenser-receiver I and as a consequence of the action of thethermostatic valve 52, the pressure on the suction side of the propanecompressor I3a progressively decreases. This pressure is communicated toa low pressure control 59 by means of a tube 69 which is connected tothe low pressure side of the compressor I3a. This low pressure control59 breaks the circuit of the motor I3c driving the propane comminimumpressure has been reached and that 52 and the operation of thecompressor I3a, there is a sudden reduction of pressure in the expansionvalve 52 which causes ebullition of the propane refrigerant in the coil42 which absorbs the latent heat from the ethane gas in thereceivercondenser I and cauces its condensation.

The oil, which has, been separated from the propane refrigerant, isconducted back to the crankcase of the compressor I3a in a manner.exactly analogous to that used on the ethane compressor, and iscontrolled by the fioat system 43a controlling the electro-magneticvalve 5b and a visible resistance lamp 46a.

Mention has heretofore been made of the bulb 9 of the. thermostaticswitch 25 whichv is in thermal contact with the suction line 1connecting the cold chamber with the ethane compressor I3 of element B.The function of this bulb and its attached control will .now beexplained.

When the temperature of the annulus of the cold chamber has been reducedto the point where there is relatively small difference between suchtemperature and that of the liquid ethane as it issues from the magneticvalve 5 through the pipe 50, the ebullition of the liquid refrigerant inthe annulus will cause some of it to pass out of the cold chamber orevaporator 6 through the v a suction line I and contact with the bulb 9of the thermostatic control 25 of element B. When compressor also ceasesoperation. A heater or stabilizer 520, such as is shown in myapplication Serial Number 423,023 now Patent No. 2,- 391,030 grantedDecember 18, 1945, placed around the expansion valve 52 to avoid anytrouble which might be caused by ice forming within the valve.

When the suction line contact with the thermostatic bulb 9 becomeswarmer, due to the contact of the ambient atmosphere, the pressure inthis bulb causes the thermostatic control 25 to close, thus permittingcurrent to again flow through the magnetic valve 5 and admittingrefrigerant into the annulus of the cold chamber. This is accompanied bya rise of pressure which, actuating the low pressure bulb of the dualpressure control 51, again causes it to reestablish the circuit in themotor I3b driving the ethane compressor I3 of element B. This compressorI3, now again driving heat to the cooling coil 42 in receiver-condenserI, causes a rise of pressure'in the crankcase of compressor I3a which,being connectedby a tube 60 to the low pressure control 59 reestablishesthe circuit of the motor I3c driving the compressor I31: and the machineis again in full operation. If at any time the propane compressor I3ashould fail to operate for any reason and thereby fail to absorb theheat which the ethane compressor I3 is pouring onto the cooling coil 42,there will be a progressive rise oi pressure in the oil separator 39 andits associated parts. This, being connected by means of a tube 6| to thehigh side of the dual pressure control 51, causes it to break thecircuit of the motor I3b driving compressor I3 and stopping further riseof pressure except that occasioned by infiltration of heat fromatmosphere to the refrigerant in the receiver-condenser I.

' Fig. 16 shows that oil separators 39 and 30a are mounted within a canor covering 62 and spaced therefrom so as to provide room for theinsulation 63, inasmuch as it is designed to avoid any heat transferfrom these units. The separator 39a is provided with the electricheaters 30b to keep the oil in a sufficiently warm condition to preventthe condensation of propane within the 9 in referring to Fig. 19 thatthe receiver-condenser is provided with a similar jacket 84, also forthe purpose of providing space for insulation 65. This insulation isprovided because, under normal circumstances, this receiver-condenser isat a sub-zero temperature and valuable refrigeration would be lost,besides the unsightly effect of condensation on its surface, if it werenot provided with proper insulation.

The electro-magnetic valve, illustrated in Figs. 9 to 13, will now beexplained in detail.

This electro-magnetic valve may be divided into two main units ordivisions, namely, the mechanical portion and the electrical portion.The electrical portion consists of an iron-clad electro magnet,comprising a magnet core 68, an enlarged portion of which constitutesone pole face of the electro-magnet, and the opposite end of the core 61terminating in a tapered neck which engages with a soft steel yoke 68,which yoke in turn engages with a magnet shell 69. Before pressing theyoke 88 onto the tapered neck of the core 61, a core insulator 18 isplaced around the cylindrical portion of the core, and coil washers iiare in turn placed around the core insulator H8.

The terminal plates 12 are soldered to terminal screws 13 and, inconjunction with a three-hole fiber disc 74, are also placed in positionaround the core insulator 18, after which the steel yoke 58 is pressedin place. The winding of magnet wire is then applied,one end of thewinding being attached to each of the two terminal plates l8 and therebyto each of the two terminal screws it. It will be noticed that theseterminal screws 19 are electrically insulated from the steel yoke 88 byan insulating bushing 15, so that the winding is insulated fromelectrical contact with the iron portions of the electro-magneticstructure. The soft steel shell 89 is then pressed in place around thesteel yoke 68 so that the enlarged face N of the core 68 and theinwardly projecting face I88 of the shell 99 lie in the same plane. Theshell 89 is then securely attached to the yoke 88 by means of electricwelding. To the face of the yoke opposite the winding is applied one oftwo magnet insulating washers l8 and retained by means of the thin flathead of the terminal screw ll. Another magnet insulating washer 16a isplaced over the terminal post 11 and broughtv into contact with theopposite side of the thin flat head thereof from the other magnetinsulating washer 16. This entire unit is now placed within the brasschamber 18. The terminal screws 11, passing through a post bushing 19placed within enlarged holes in the end of the brass chamber 18, performtwo functions: They support the iron-clad magnet structure within thebrass chamber; and they seal the holes in the brass chamber 18 by theeffect of the flat heads on the terminal screws 11 and magneticinsulating washers I8 and 16a which cover these enlarged holes andprevent leakage therethrough.

The outer washer 18a is held in intimate contact with the end of thebrass chamber I8 by means of the following assembly construction: Aterminal insulator 19a is placed over the ends of the terminal screws TIagainst the end of the brass chamber 18. Then there is a post washer 88and a terminal post spring 8|, another brass washer 82 and finally'hexnuts 83 are screwed onto the terminal posts 11, holding everythingfirmly in place by compressing the terminal post spring 8|. Before theiron-clad magnet is assembled, the magnet washers 18 and 18a are paintedwith very heavy shellac which assists materially in preventing leakagebetween the washeis 16 and 18a and the end of the brass chamber Themechanical portion of the valve consists of an inlet fitting 84a screwedinto the side of the brass chamber-I8 and an outlet fitting 84 which is,screwed into the plate 85 and is anchored there against the possibilityof turning by means of a key 86, as shown in Fig. 9, which is driveninto a hole drilled in the pitch line of the thread (shown near thethread for clearness) uniting the plate 85 with the fitting 84. Theportion of the fitting 84, which extends beyond the plate 85, is reducedin diameter to serve as a guide for two cylindrical posts 81 and arectangular post 88, hereinafter to be described.

The central hole in the extended portion of the fitting 84 istaper-reamed to receive the tapered end of valve seat 89, while clampedbetween the head of the valve seat 89 and fitting 84 is 7 an abutmentscrew support 98. This screw support 98 supports a plain abutment screw9| and a slotted abutment screw 92, the free ends of which screws extendinto properly placed holes in the plate 85, the abutment screws eachcarrying a hex nut 93 with which to adjust their axial location. A valveplate 94 is provided with three small steel balls 95, 98, 91 welded orotherwise anchored thereto,.two of which, by engagement with abutmentscrews 92 and 9|, serve as hinge members for the valve plate, the otherone of which serves as the valve member engaging with the valve seat 89.The valve plate 94 is provided with a countersunk hole, symmetricallylocated with respect to the two hinge balls and approximately one-thirdof the distance between a line joining the two hinge balls and the valveballs. Through this countersunk hole passes the flat head machine screw98, which engages a few turns of the valve spring 99 by being screwedinto the interior of said spring, the convolutions of the spring servingas threads. The other end of the spring 99 is engaged with a headlessscrew I88 by similar'means, and this headless screw is connected withthe plate by being screwed into a hole tapped therein. By means of thiscombination of screws 88 and 98 and spring 99, a strain is applied tothe valve plate 94, which holds the hinge balls into contact with theabutment screws 92 and 9| and the valve ball into valving relation withthe valve seat 89. An armature |8| is provided which, when the plate 85is screwed into the open thread end of the brass chamber 18, is broughtinto fairly close juxtaposition with the pole faces of the iron-cladelectro-magnet. The lateral location of the armature |8| is secured bymeans of two cylindrical posts 8'! and a post of rectangular section 88,these posts being securely fastened to armature |8| by means of flathead screws I84, as previously described. These posts are located aboutthe reduced extended portion of fitting 84 so as to keep armature 8|centrally located about the fitting 84, and at the same time maintain aproper clearance between the armature and the valve plate 94.

The small end of the Valve Plate 94 (Fig. 13) is extended to engage withthe projecting part of the rectangular post 88. By means of thisrelation between the valve plate 94 and the rectangular post 88, thearmature |8|, when attracted by the electro magnetic effect of theironclad magnet assembly, raises the extended end of the valve plate 94,thus lifting the valve ball from the seat 89 until armature IOI contactsthe pole faces I05 and I09 of the electro-magnet assembly. This movementof the armature and of the valve plate is resisted by the retractileeffect of spring 99 so that upon the discontinuance of the current inthe electro-magnet, the spring 99 causes the valve plate 90 and armatureIM to have a return movement until the valve ball flts into the seat 89and the posts 81 and 88 are stopped by the plate 85. It will be notedthat the presence of posts 81 and 88 prevent the mass of armature IOIfrom the seat 89, also that this construction eliminates any tendency ofthe hinge balls being lifted from the abutment screws 92 and 9|.

It is also worthy of note that the use of the triangular relation of thevalve orifice in the valve seat 89, the slot abutment 92 and the plainabutment screw 9| definitely locate the valve plate 94, both withrespect to the plane occupied by the plate and its angular relationabout the axis of the fitting 80.

hammering the valve ball into After the plate 85 has been screwed intothe open end of the brass chember 18 a proper distance, .so as toprovide for the proper gap between the armature WI and the pole facesI05 and I09, the body is hermetically sealed by closing the intersticebetween plate 85 and chamber 19 by means of a relatively low meltingpoint solder, at the same time hermetically sealing the tapped holethrough which passes the headless screw I00 and also the intersticebetween the fitting 80 and the plate 95. The fluid to be valved entersthe brass chamber 18 through a side fixture 94a; as shown in Fig. 10,and then its pressure tends to assist the spring 99 in holding the valveshut so that the electro-magnetic attraction, which raises armature I0l,must be sufllciently powerfulto lift the valve from its seat against thepressure of the fluid within the brass chamber in addition to flexingthe spring 99. Manually operated switches I01, I08 and I09 are providedto allow minor repairs or adjustments without shutting down the entireapparatus.

Fig. 21 is a diagrammatic view of the electric circuits used in thisapparatus. The current is preferably fed from a 220-110 volt, three-wiresystem, being connected by means of a polarized three-prong connectorH0. as shown at extreme upper left of Fig. 21. The 220 volt circuit ofthe two outer conduc ors is conducted from the conductor III, throughdual pressure control 51, through the ethane motor I3b. and back to theother 220 volt conductor II2; also from the conductor III through thelow pressure control 59, through the propane motor I30. and back to theconductor I I2, thus operating the two motors on 220 volts when theirrespective switches are closed. The current is also led from conductorIII through the right hand side of switch I09, through oil separatorheaters b, in parallel with each ,other and wi h the propane expansionvalve stabilizer 52,0, and also in parallelwith a series circuitcontaining consecutively propane oil float switch 43a, bulb 46a, andmagnetic valve 5b. The entire current of these parallel units traversesthe left side of the switch I09 to the neutral or grounded conductor 3,thus connecting the parallel circuits to a 110 volt circuit. Currentfrom the 220 volt conductor H2 is led to the left side of switches I01and I08. Current from the switch I01 passes through a series circuitconsisting of the ethane oil float switch 43, bulb a, and the magneticvalve 5a, and from there through the right side of switch I01 to thegrounded neutral conductor II3. From the left side of switch I08,current passes through a series circuit, comprising ethane frost backthermostatic control 25, ethane suction throttling contactor .21, bulb29, magnetic expansion valve 5, then through the right side of switchI08 tothe grounded neutral conductor 8, thus applying volts across thisseries circuit.

It will thus be seen that current is travelling through the oilseparator heaters 30b and the valve stabilizer 520 all the time that theplug is inserted in the line, and the switch I09 is thrown into the on"position, and that the current through the magneticvalve 5b, controllingthe propane oil system is controlled by the action of propane oil floatswitch 43a at all times when switch I09 is thrown in the on position. Itis also evident that when switch I08 is thrown in the "on position, theflow of current through the magnetic expansion valve 5, and thereforethe flow of refrigerant into the system, is controlled by the combinedaction of the ethane frost-back thermostatic control 25 and the ethanesuction throttling contactor 21, and that when the switch I01 is thrownin the on position, the flow of current through the ethane oil systemmagnetic valve 5a, which controls the motor I3c is controlled by thepropane low pressure control 59. 1

In addition to the general apparatus and process, wherein the heat isremoved from'the gas leaving the evaporator in two stages, it will beseen from the foregoing that there is provided a refrigerating expansionvalve system wherein there is electro-magnetic means for introducingliquid refrigerant into the evaporating space and an auxiliary spacecontaining a fluid having a pressure controlled by the temperature ofthe refrigerated space. There is an electrical switch means, responsiveto the differential of pressure between that of the evaporating spaceand that in the auxiliary space for electrically controlling theintroduction of the refrigerant by the elec-' tro-magnetic means.

There is also provided a system for condensing the heated vapor,comprising velocity actuated means for mixing condensed liquid with theincoming superheated vapor to reduce the amount of superheat by theevaporation of the liquid.

It will further be seen that there is an apparatus constituting a liquidsprayer means for spraying liquid and gas, there being means foraccelerating the velocity of the gas and its entrapped liquid and forejecting them against a liquid removal surface, and means for retardingthe velocity of the gas, partially dispossessed of its liquid, andmoving it to a place where it is brought again under the influence ofmeans for accelerating and ejecting, and the successive repetition ofthese means, so as to separate completely the entrapped liquid from thegas, and means for collecting the successive liquid separations into oneunit.

I claim:

1. A refrigerating apparatus which includes an evaporator through whicha refrigerant is passed, said evaporator being in the form of acontainer surrounding a space adapted to receive material to be treated,a super heat suppressing apparatus including a Venturi tube to which therefri erant, after passing through the evaporator, is delivered, a heatremoving apparatus to which the refrigerant is delivered from the superheat suppressing device and which removes heat therefrom, and means fordelivering said refrigerant to the evaporator.

2. A refrigerating apparatus which includes an evaporator through whicha refrigerant is passed, said evaporator being in the form of acontainer surrounding a space adapted to receive material to be treated,a super heat suppressing apparatus to which the refrigerant, afterpassing through the evaporator, is delivered, a heat removing apparatusto which the refrigerant is delivered from the super heat suppressingdevice, said heat removing device being provided with a differentrefrigerant from that used in the super heat suppressing apparatus, acoil through which the cooled refrigerant of the heat removing device ispassed, a container for said coil, the cooled refrigerant from the superheat suppressing apparatus being passed through said container so as tobe further cooled thereby, and means for returning said refrigerant tosaid evaporator.

3. A low temperature refrigerating apparatus comprising three generalelements, an evaporator for cooling the material, said evaporator beingin the form of a container surrounding a space adapted to receive thematerial to be cooled, said evaporator using a volatile refrigerant, asuper heat suppressing device including a Venturi tube for removing heatfrom this refrigerant and a separate heat removing device for removingfurther heat from the refrigerant used in the evaporator.

4. In-a refrigeration apparatus, a base, an evaporator-container on saidbase, including an evaporator surrounding and defining a space adaptedto receive the material to be treated, a compressorecondenser on saidbaseyin circuit with said evaporator, a second compressor-condenser onsaid base, a condenser receiver on said base, in circuit with saidfirst-mentioned compressor-condenser and evaporator, an evaporator coilin said condenser receiver, in circuit with said secondcompressor-condenser, and means for actuating said compressors, thecircuits which include said compressors being each provided with arefrigerant, the refrigerants of the two systems being of differentvolatility.

5. In a refrigeration apparatus, a base, an open toppedevaporator-container on said base, including an evaporator surroundingand defining a space adapted to receive the material to be treated, acompressor on said base. in circuit with said evaporator, and acondenser receiver in circuit therewith, a second compressor and acondenser coil on said base, an evaporator coil, in circuit therewith,positioned within said condenser receiver, the circuits thus formedbeing provided each with a refrigerant, and means for simultaneotgslyactuating the compressors of the two circul 6. In a refrigerationapparatus, an evaporatorcontainer including an evaporator surroundingand defining a space adapted to receive the material to be treated, acompressor, and a condenser receiver, in circuit with said evaporator, asecond compressor and condenser coil, and an evaporator coil in circuittherewith, said evaporator coil being positioned within said condenserreceiver, the circuits thus formed being provided each with arefrigerant, and means for actuating the compressors of the twocircuits.

WILLARD L. MORRISON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

